Electronic timepiece with positionable rotor

ABSTRACT

In an electronic timepiece, the rotor bears, in addition to the usual pinion gear, a cam. Pulling the watch stem outward makes it possible to stop the rotor as well as the second hand of the timepiece which is connected to the rotor, at a pre-selected position by means of the cam. Pushing the stem inward restarts the rotor. In this way, the second hand can be synchronized with an external time signal. The stator has a plurality of functions, making it possible to reduce the size of such timepieces.

United States Patent 1 1 Kamijo July 10, 1973 [54] ELECTRONIC TIMEPIECE WITH POSITIONABLE ROTOR [7 5] Inventor: Noriyuki Kamijo, Tatsuno-Machi,

Japan [73] Assignee: Kabushiki Kaisha Suwa Seikosha, Tokyo, Japan [22] Filed: Feb. 25, 1972 [21] Appl. No.: 232,317

[30] Foreign Application Priority Data Mar. 3, 1971 Japan 46110789 [52] US. Cl. 58/34, 310/41 [51] Int. Cl G04c 9/00 [58] Field of Search 58/23 R, 34, 35, 58/855; 310/41, 77; 318/138, 254

[56] References Cited UNITED STATES PATENTS 3,432,699 3/1969 Albinger, Jr. 310/41 3,614,492 10/1971 Yatsushiro et a1. 310/41 Primary Examiner--George H. Miller, Jr. AttorneyA1ex Friedman, Harold 1. Kaplan and James K. Silberman [5 7 ABSTRACT 7 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION I The design of timepieces, and in particular, electronic wrist-watches is now such that the accuracy with which such time-pieces keep time is great enough to warrant the attempt to synchronize the timepiece to the nearest second. The mechanism required for this objective can be relatively complex and consequently bulky as well as heavy. This is undesirable, since such watches may be sufficiently heavy to be uncomfortable to the wearer.

SUMMARY OF THE INVENTION An electronic timepiece has a rotor to which is affixed a cam for positioning the rotor in a pre-selected position. The stator is polyfunctional in that it serves for driving the rotor in response to electrical circuitry which generates pulses in alternating directions, and in addition serves to support a positioning lever which can stop the rotor in any of a plurality of preselected positions and thereby stop the second-hand of the timepiece at a pre-selected position, preferably the zero position. The timepiece can be restarted by moving the stem of the timepiece in an inward direction. In this manner, it is possible to synchronize the watch with an external signal to the nearest second.

Using the stator of the timepiece for a plurality of functions makes it possible to reduce the over-all size of the timepiece and to reduce the number of parts, weight and cost of the timepiece, as well as making it more suitable for mass-production.

Accordingly, an object of the present invention is to provide an improved electronic timepiece in which the stator serves a plurality of functions.

Another object of the present invention is to provide an improved electronic timepiece which can readily be adjusted to the nearest second.

A further object of the present invention is to provide an improved electronic timepiece which is reduced in size, weight and cost over conventional timepieces.

Still another object of the present invention is to provide an improved electronic timepiece which is suitable for mass-production.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a graph of pulses produced by the electronic circuitry of an electronic timepiece in accordance with the present invention;

FIG. 2 is a plan view of the drive and control portions of an electronic timepiece in accordance with the present invention; and

FIG. 3 is an elevational view of the mechanism shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT A stator 1 has a portion 18 around which is wrapped coil 17. Coil 17 is pulsed by drive circuit 19 operating in combination with reset circuit 20. Drive circuit 19 and reset circuit 20 together comprise the electronic circuitry indicated generally by 21. The electronic circuitry supplies pulses to coil 17 in the form shown in FIG. 1. In the state shown in FIG. 2, poles 22 of stator l are south poles, and poles 23 of stator l are north poles. Rotor 3 is mounted on shaft 14 and, in the embodiment shown in FIG. 2, has three south poles and three north poles in alternating sequence. The altemating pulses supplied by coil 17 reverse the polarity of poles 22 and poles 23 once per second, advancing rotor 3, 60 with each pulse. Firmly affixed to shaft 14 is cam 4 which is three-lobed. Cam 4 can take either of two positions as indicated by the phantom lines and is given the reference numerals 4a and 4b.

Cam positioning lever 5 is movable between two positions indicated as 5a and 5b. For this movement, lever 5 is pivotedly mounted on stator l by means of pin 11. Lever arm 24 is urged by spring 6 toward position 5b. Stern 7 can be moved inwardly and outwardly from the exterior of the timepiece. When in the inward position, stem 7 holds positioning lever 5 in position 5a by engagement with pin 15, affixed to lever 5. Moving stem 7 in outward direction disengages stem 7 from pin 15 and allows positioning lever 5 to rotate clockwise until arm 24 makes contact with pin 9 in insulating sleeve 8 affixed to stator 1. Pin 9 and stator 1 are both electrically connected to reset circuit 20. The relationship between reset circuit 20 and drive circuit 19 is such that completing the external circuit of reset circuit 20 halts drive circuit 19 and stops the generation of current pulses. Simultaneously, reset lever 5 moves into contact with cam 4 and brings cam 4 into position 4a.

When stem 7 is in the outward position, crown gear 10 makes contact with a back-gear train (not shown) by means of which the minute and the hour hand of the timepiece may be adjusted.

Shaft 14 carries pinion gear 26 which makes contact with gear 12, the number of teeth on gears 12 and 26 being such that gear 12 makes 1 revolution in 1 minute. By selecting the instant at which stem 7 is pulled outwardly, the second hand carried by gear 12 can be stopped at any even-numbered second, preferably zero. The watch can then be restarted by pushing stem 7 inwardly in synchronization with an external signal, thereby adjusting the timepiece to the nearest second. As can be seen from FIG. 2, pushing the stem 7 inwardly displaces pin 15 downwardly and rotates positioning lever 5 to position 5a. This releases cam 4 and rotor 3. and simultaneously breaks contact between lever arm 24 and pin 9, thus starting the flow of current pulses from the electronic circuitry.

By well-known methods, slip is provided between gear 12 on the shaft of which the second-hand is mounted and the remainder of the back-gear train so that the minute and hour hands can be adjusted while gear 12 is held in fixed position. The movement of crown gear 10 into and out of mesh with the back-gear train involves the use of yoke 16 which, again, is conventional. However, the use of the stator l for supporting the various components described, makes it possible to position crown gear 10 very precisely with relation to the stator 1, so that the distance between them as indicated in FIG. 3 by 8 can be held to a very small value, thereby effecting a substantial reduction in the thickness of the timepiece.

As is evident, there is nothing inherent in the design of the timepiece described which makes it necessary that cam 4 have only three lobes. It is only necessary that the number of poles on rotor 3 have the appropriate correspondence with the number of lobes on cam 4. Similarly, the frequency of the pulses supplied by electronic circuitry 21 could be a multiple or a submultiple of the one-second frequency specified in the above description, without significant change in the invention disclosed herein.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above article without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Wat is claimed is:

1. An electronic timepiece comprising driving circuitry for generating pulses alternating in polarity at pre-selected intervals, a stator connected to said circuitry for receiving said pulses, a rotor within said stator and rotatable at a pre-selected rate by said stator in response to said pulses, a positioning cam mounted on said rotor for moving said rotor to and holding said rotor at a pre-selected position, a positioning lever for stopping said cam at a pre-selected position, said positioning lever being pivotedly mounted on said stator, a stem slidable exteriorly of said timepiece in an axial direction toward and from the interior of said timepiece, and spring means urging said positioning lever toward said positioning cam, said positioning lever being so related to said stem and said driving circuitry, that movement of said stem from the interior of said timepiece allows said spring means to move said positioning lever into contact with said cam, halting said rotor in a preselected position and simultaneously disconnecting said circuitry and stopping the production of driving pulses, and moving said stem toward the interior of said timepiece disengages said positioning lever from said cam thereby eliminating the constraint of said rotor from rotating and reconnecting said driving circuitry for the production of pulses for driving said rotor.

2. The electronic timepiece as defined in claim 1, wherein said stem has a third gear mounted thereon and said timepiece has therein a back-gear train on which are mounted the minute and hour hands of said timepiece, said third gear engaging said backgear train for setting said minute and hour hands only when said stem is in outwardly-moved position and said driving circuitry is disconnected.

3. The electronic timepiece as defined in claim 1, wherein said cam has three lobes, thereby making it possible to stop and hold said rotor in any of three positions.

4. The electronic timepiece as defined in claim 1, further comprising an axially-slidable stem, a positioning lever, a pin and a sleeve insulator, said lever being pivotedly mounted on and having electrical continuity with said stator, said stator having an aperture in which is firmly fixed said sleeve insulator, said pin being fixed in said sleeve, said electronic circuitry being connected by one lead to said stator and by a second lead to said pin, the relationship among said lever, stem and pin being such that outward movement of said stem bring said lever into mechanical and electrical contact with said pin thereby completing a circuit which halts the generation of pulses by said circuitry.

'5. An electronic timepiece as defined in claim 1 comprising driving circuitry for generating pulses alternating in polarity at pre-selected intervals, a stator connected to said circuitry for receiving said pulses, a rotor within said stator and rotatable at a pre-selected rate by said stator in response to said pulses, said stator serving as base means for the support of other components of said timepiece.

6. The electronic timepiece as defined in claim 1, wherein said rotor has thereon a first pinion gear and said timepiece has a second pinion gear meshing with said rotor pinion, saidsecond gear having an axle on which is mounted the second hand of said timepiece, thereby making it possible to halt said second hand at a pre-selected position by outward movement of said stern, and to restart said second hand in synchronization with an external signal by inward movement of said stem.

7. The electronic timepiece as defined in claim 6, wherein said electronic circuit generates one pulse per second and said rotor has three south and three north magnetic poles in alternating sequence, the positioning of said second hand in relationship to said rotor and positioning cam being such that said second hand can be stopped at any even-numbered second including zero. -4 a: e 

1. An electronic timepiece comprising driving circuitry for generating pulses alternating in polarity at pre-selected intervals, a stator connected to said circuitry for receiving said pulses, a rotor within said stator and rotatable at a preselected rate by said stator in response to said pulses, a positioning cam mounted on said rotor for moving said rotor to and holding said rotor at a pre-selected position, a positioning lever for stopping said cam at a pre-selected position, said positioning lever being pivotedly mounted on said stator, a stem slidable exteriorly of said timepiece in an axial direction toward and from the interior of said timepiece, and spring means urging said positioning lever toward said positioning cam, said positioning lever being so related to said stem and said driving circuitry, that movement of said stem from the interior of said timepiece allows said spring means to move said positioning lever into contact with said cam, halting said rotor in a preselected position and simultaneously disconnecting said circuitry and stopping the production of driving pulses, and moving said stem toward the interior of said timepiece disengages said positioning lever from said cam thereby eliminating the constraint of said rotor from rotating and reconnecting said driving circuitry for the production of pulses for driving said rotor.
 2. The electronic timepiece as defined in claim 1, wherein said stem has a third gear mounted thereon and said timepiece has therein a back-gear train on which are mounted the minute and hour hands of said timepiece, said third gear engaging said backgear train for setting said minute and hour hands only when said stem is in outwardly-moved position and said driving circuitry is disconnected.
 3. The electronic timepiece as defined in claim 1, wherein said cam has three lobes, thereby making it possible to stop and hold said rotor in any of three positions.
 4. The electronic timepiece as defined in claim 1, further comprising an axially-slidable stem, a positioning lever, a pin and a sleeve insulator, said lever being pivotedly mounted on and having electrical continuity with said stator, said stator having an aperture in which is firmly fixed said sleeve insulator, said pin being fixed in said sleeve, said electronic circuitry being connected by one lead to said stator and by a second lead to said pin, the relationship among said lever, stem and pin being such that outward movement of said stem bring said lever into mechanical and electrical contact with said pin thereby completing a circuit which halts the generation of pulses by said circuitry.
 5. An electronic timepiece as defined in claim 1 comprising driving circuitry for generating pulses alternating in polarity at pre-selected intervals, a stator connected to said circuitry for receiving said pulses, a rotor within said stator and rotatable at a pre-selected rate by said stator in response to said pulses, said stator serving as base means for the support of other comPonents of said timepiece.
 6. The electronic timepiece as defined in claim 1, wherein said rotor has thereon a first pinion gear and said timepiece has a second pinion gear meshing with said rotor pinion, said second gear having an axle on which is mounted the second hand of said timepiece, thereby making it possible to halt said second hand at a pre-selected position by outward movement of said stem, and to restart said second hand in synchronization with an external signal by inward movement of said stem.
 7. The electronic timepiece as defined in claim 6, wherein said electronic circuit generates one pulse per second and said rotor has three south and three north magnetic poles in alternating sequence, the positioning of said second hand in relationship to said rotor and positioning cam being such that said second hand can be stopped at any even-numbered second including zero. 